docs: fix compatibility table for perses dashboards feature (#714)

Signed-off-by: Gabriel Bernal <[email protected]>

Author: jgbernalp

docs/user-guides/observability-ui-plugins.md

@@ -189,5 +189,5 @@ spec:
 | __COO Version__ |   __OCP Versions__  | __Features__                      |
 | --------------- | ------------------- | --------------------------------- |
 | 1.0.0+          | 4.14+               | `acm-alerting`                    |
-| 1.1.0+          | 4.14+               | `acm-alerting, perses-dashboards` |
+| 1.1.0+          | 4.15+               | `acm-alerting, perses-dashboards` |
 | 1.1.0+          | 4.18+               | `acm-alerting, perses-dashboards, incidents` |